drivers/rtc/rtc-sd2405al.c

Source file repositories/reference/linux-study-clean/drivers/rtc/rtc-sd2405al.c

File Facts

System
Linux kernel
Corpus path
drivers/rtc/rtc-sd2405al.c
Extension
.c
Size
5922 bytes
Lines
230
Domain
Driver Families
Bucket
drivers/rtc
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct sd2405al {
	struct device		*dev;
	struct regmap		*regmap;
};

static int sd2405al_enable_reg_write(struct sd2405al *sd2405al)
{
	int ret;

	/* order of writes is important */
	ret = regmap_update_bits(sd2405al->regmap, SD2405AL_REG_CTR2,
				 SD2405AL_BIT_WRTC1, SD2405AL_BIT_WRTC1);
	if (ret < 0)
		return ret;

	ret = regmap_update_bits(sd2405al->regmap, SD2405AL_REG_CTR1,
				 SD2405AL_BIT_WRTC2 | SD2405AL_BIT_WRTC3,
				 SD2405AL_BIT_WRTC2 | SD2405AL_BIT_WRTC3);
	if (ret < 0)
		return ret;

	return 0;
}

static int sd2405al_disable_reg_write(struct sd2405al *sd2405al)
{
	int ret;

	/* order of writes is important */
	ret = regmap_update_bits(sd2405al->regmap, SD2405AL_REG_CTR1,
				 SD2405AL_BIT_WRTC2 | SD2405AL_BIT_WRTC3, 0x00);
	if (ret < 0)
		return ret;

	ret = regmap_update_bits(sd2405al->regmap, SD2405AL_REG_CTR2,
				 SD2405AL_BIT_WRTC1, 0x00);
	if (ret < 0)
		return ret;

	return 0;
}

static int sd2405al_read_time(struct device *dev, struct rtc_time *time)
{
	u8 data[SD2405AL_NUM_T_REGS] = { 0 };
	struct sd2405al *sd2405al = dev_get_drvdata(dev);
	int ret;

	ret = regmap_bulk_read(sd2405al->regmap, SD2405AL_REG_T_SEC, data,
			       SD2405AL_NUM_T_REGS);
	if (ret < 0)
		return ret;

	time->tm_sec = bcd2bin(data[SD2405AL_REG_T_SEC] & 0x7F);
	time->tm_min = bcd2bin(data[SD2405AL_REG_T_MIN] & 0x7F);

	if (data[SD2405AL_REG_T_HOUR] & SD2405AL_BIT_24H)
		time->tm_hour = bcd2bin(data[SD2405AL_REG_T_HOUR] & 0x3F);
	else
		if (data[SD2405AL_REG_T_HOUR] & SD2405AL_BIT_12H_PM)
			time->tm_hour = bcd2bin(data[SD2405AL_REG_T_HOUR]
						& 0x1F) + 12;
		else /* 12 hour mode, AM */
			time->tm_hour = bcd2bin(data[SD2405AL_REG_T_HOUR]
						& 0x1F);

	time->tm_wday = bcd2bin(data[SD2405AL_REG_T_WEEK] & 0x07);
	time->tm_mday = bcd2bin(data[SD2405AL_REG_T_DAY] & 0x3F);
	time->tm_mon = bcd2bin(data[SD2405AL_REG_T_MON] & 0x1F) - 1;
	time->tm_year = bcd2bin(data[SD2405AL_REG_T_YEAR]) + 100;

	dev_dbg(sd2405al->dev, "read time: %ptR (%d)\n", time, time->tm_wday);

	return 0;
}

static int sd2405al_set_time(struct device *dev, struct rtc_time *time)
{
	u8 data[SD2405AL_NUM_T_REGS];
	struct sd2405al *sd2405al = dev_get_drvdata(dev);
	int ret;

	data[SD2405AL_REG_T_SEC] = bin2bcd(time->tm_sec);
	data[SD2405AL_REG_T_MIN] = bin2bcd(time->tm_min);
	data[SD2405AL_REG_T_HOUR] = bin2bcd(time->tm_hour) | SD2405AL_BIT_24H;
	data[SD2405AL_REG_T_DAY] = bin2bcd(time->tm_mday);
	data[SD2405AL_REG_T_WEEK] = bin2bcd(time->tm_wday);
	data[SD2405AL_REG_T_MON] = bin2bcd(time->tm_mon) + 1;
	data[SD2405AL_REG_T_YEAR] = bin2bcd(time->tm_year - 100);

Annotation

Implementation Notes